Trends in foodborne pathogen detection
An impedimetric immunosensor has been described for
L. monocytogenes whereby the pathogen is captured and
concentrated using IMS then 20 ml of the captured beads
are flowed over a series of interdigitated electrodes
(Kanayeva et al., 2012). The presence of Listeria resulted
in a change in impedance at 102 Hz although was not found
to be concentration dependent. In simple buffer solution the
detection limit for the assay was 3 log cfu/ml. However, in
lettuce rinse samples, milk or homogenated ground beef
samples the sensitivity of the assay was decreased with a
detection limit of 4 log cfu/ml with high variation in sensor
response being observed (Kanayeva et al., 2012). The
sensor response was significantly lower when Listeria was
introduced into beef homogenate compared to lettuce rinse
solution and milk. The relatively low sensitivity of the
assay was attributed to interference of Listeria capture